Reduce bundle size

Replace @actions/core with local functions

@actions/core is unmaintained and poorly designed for projects that just need basic functions

package.json

@@ -34,7 +34,6 @@
   "author": "shivammathur",
   "license": "MIT",
   "dependencies": {
-    "@actions/core": "^1.11.1",
     "@actions/exec": "^1.1.1",
     "@actions/io": "^2.0.0",
     "compare-versions": "^6.1.1"
@@ -49,6 +48,7 @@
     "@vercel/ncc": "^0.38.4",
     "eslint": "9.39.1",
     "eslint-config-prettier": "^10.1.8",
+    "eslint-import-resolver-typescript": "^4.4.4",
     "eslint-plugin-import": "^2.32.0",
     "eslint-plugin-jest": "^29.2.1",
     "eslint-plugin-prettier": "^5.5.4",
@@ -63,8 +63,7 @@
   },
   "overrides": {
     "test-exclude": "^7.0.1",
-    "glob": "^11.1.0",
-    "undici": "^6.23.0"
+    "glob": "^11.1.0"
   },
   "bugs": {
     "url": "https://github.com/shivammathur/setup-php/issues"